- Jul 19, 2021
- Reaction score
2-(5-Methoxy-1H-indol-3-yl)-N,N-dimethylethan-amine (5-Meo-DMT freebase).
1. To a clean and dry 5 L reactor was charged 4-methoxyphenylhydrazine hydrochloride (145.0 g; 0.83 mol, 1.0 equiv), followed by water (1.45 L, 10 vol) under a nitrogen atmosphere at 20−25 *C.
2. The contents of the reactor were then stirred at 30−35 *C and a dark red colored suspension was observed.
3. To the suspension, concentrated H2SO4 (47.7 ml, 0.91 mol, 1.1 equiv) was cautiously added dropwise under a nitrogen atmosphere over 10 min while maintaining the temperature below 40 *C (slightly exothermic).
4. The brown/red solution was heated to 35−40 *C (with a target temperature of 37 *C) and stirred for an additional 10 min.
5. A solution of 4,4-diethoxy-N,N-dimethyl-butan-1-amine (165.0 g, 0.87 mol, 1.05 equiv) was prepared in acetonitrile (0.58 L, 4.0 vol), and added dropwise to the reactor under a nitrogen atmosphere over approximately 60 min while maintaining the temperature between 35 and 40 *C.
6. The addition funnel was rinsed with acetonitrile (145 ml, 1.0 vol) and added dropwise to the reactor.
7. The temperature was maintained at 40 *C, and the contents were agitated for an additional 4 h.
8. The mixture was cooled to 20−25 *C and the contents were transferred to a 10 L reactor.
9. The acidic aqueous solution was washed with 2-MeTHF (2x2.03L, 14.0 vol).
10. After each wash, the layers were allowed to settle for 15 min.
11. The lower acidic aqueous layer was collected and the upper 2-MeTHF wash was discarded.
12. The acidic aqueous layer was recharged to the reactor and sodium hydroxide solution (4 M, 0.65 L, 4.5 vol) was added dropwise while maintaining the temperature at 20−25 *C to bring the pH to 11−12 providing a milky suspension.
13. The suspension was extracted with 2-MeTHF (3x1.45 L, 10.0 vol); following each extraction, the layers were allowed to settle for 15 min, the lower alkaline water layer was separated into a drum, and the upper organic layer was collected.
14. The lower aqueous layer was discarded and the combined 2-MeTHF organic layers were transferred to a 20 L-flask.
15. The solution was concentrated in vacuo to an oily amber residue.
16. Residual water was removed azeotropically by redissolving the residue with fresh 2-MeTHF (1.45 L, 10 vol) and repeating the concentration step.
17. This oily residue was dried on the rotatory evaporator under vacuum (10−20 mbar) for 1 h at 40−45 *C to provide 117.68 g (64.9% theoretical yield) of crude 5-MeO-DMT freebase.
Last edited by a moderator: